Lighting devices based on light emitting diodes (LEDs) are expected to replace traditional fluorescent lighting and spotlight fixtures, due to the LEDs superior properties when it comes to power consumption, endurance, size, etc.
Existing LED based lighting devices usually comprises a dedicated dual layer printed circuit board (PCB) or similar for connecting the LEDs. An example of such a LED based lighting device is disclosed for example in U.S. Pat. No. 7,083,317, wherein LEDs are mounted on a flexible wiring board. Further, light emitting surfaces of the LEDs are in contact with a light entrance end surface of a light guide plate for coupling light into the light guide plate.
However, the use of a dedicated PCB or wiring board may increase the thickness of the lighting device. Also, the dedicated PCB may imply no little cost of the lighting device.